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Three hamburgers and 2 hotdogs cost $16 and 2hamburgers and 3 hotdogs cost $14. What is the costof one hamburger and one hotdog?

User Amani
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1 Answer

13 votes
13 votes

Answer

The cost of one hamburger is $4

The cost of one hotdog is $2

Step-by-step explanation

Let a represents hamburger, and

Let b represents hotdog.

Three hamburgers and 2 hotdogs cost $16 implies;


3a+2b=16---i

Also, 2 hamburgers and 3 hotdogs cost $14 implies;


2a+3b=14---ii

Compare the system of equations and solve using elimination method


\begin{gathered} 3a+2b=16---i\text{ x 3} \\ 2a+3b=14---ii\text{ x 2} \\ \Rightarrow9a+6b=48---iii \\ 4a+6b=28---iv \\ \end{gathered}

Substract (iv) from (iii)


\begin{gathered} 9a-4a+6b-6b=48-28 \\ 5a=20 \\ D\text{ivide both sides by 5} \\ (5a)/(5)=(20)/(5) \\ a=4 \end{gathered}

Since a represent hamburger, this implies the cost of one hamburger is $4

To get the cost of one hotdog, substitute a = 4 into (i)


\begin{gathered} \text{Recall (i);} \\ 3a+2b=16---i \\ \Rightarrow3(4)+2b=16 \\ 12+2b=16 \\ 2b=16-12 \\ 2b=4 \\ \text{Divide both sides by 2} \\ (2b)/(2)=(4)/(2) \\ b=2 \end{gathered}

Therefore, the cost of one hotdog is $2

User Merilee
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